Process of making ammonia.



which cause a lowerin U TED oannn'ron ELLIS, or MoN'roLAIeuEw JERSEY.

' rzaoo nss or MAKING AMMONIA.

Specification of Letters Patent.

rammed my so, 1916.

no Drawing. Original application'filed August a, 1912, Serial No. 714,155. iiivmee and this application i filed December 15,1915, Serial No .6-3,950.

To all whom it may concern: Be t known that I, CARLETON LLLIs, a

I citizen of the United States, residing at 'Montclair, in the county of Essex and State I 6, of"New Jersey, have inventedcertain new and Iuseful 'Imp'rovementsin Processes of "Making Ammonia, of which the following is a specification. 'f

The presentinvention relates to the syn- 10 thesis of ammonia, and has for itsobj'ect the fprovision of processfwhereby ammonia can be synthetically produced, in an econominal manner, and with. a large yield per unit of contact mass, and. which process M 1.5.shallusea contact material, which is relajfltively cheap, but which is very highly efficie'nt Lin the process, and which efficiency is substantially; permanent, instead of soon "losing its activity as do many of the cataysts 2 heretofore employed.

In myqprocess, 1' preferably use as the catalyst a material contain ng a'metal of the cer um group, and particularly cerium, I as the metallic constituentof the catalyzer. The metal need not be absolutely pure, and

i in fact it'is desirable that small amountsof pnelor more of such other metals as lanthanum, didymium, lyttriu m or equivalents thereotbe present,-a s these have a consid-' erable energizing effect upon the cerium, so that .cerium contalnlng one or more of such other metals is greatly s'uperior' to the pure inetahas a catalyzer in this art forthe cat- .'.alytic production of ammonia.

.3 1ior the preparation of a suitable cata- -1yst,'I :prefe'rably proceed in the following .manne r. Cerium OXICLWVhlCll is at present a waste product of the ga's mantle industry,

and which contains usually a sufiiciently 0 large amount of the rare metals ahove'referred to, is first-'yvaslied to remove soluble salts of alkalis, -etc., and may be treated in anydesired' manner to remove impurities which act as contact poisons, or substances or ofthe catalytic.- ac tivity,-and;it is thereai ter reduced to metal.

As stated above, cerium oxid' often containssmall percentages of lanthanum, di-

activity of; the cerium, when present in amounts ofany or all of these metals, or reiducible compounds thereof may he added to dylniuin yttrium, and certain other sub-- stances which greatly enhance the catalytic described and claimed in my copending-aps plication714,155, filed August 9, 1912,:o t which this present application is a division and which application has .now matured into Patent No. 1,167,280, January 4, 19,16.

In said process granular cocoanut charcoal is first Washed or extracted with dilute acids, e. 9., by boiling with hydrochloric acid of moderate strength, to remove soluble matter, such as alkali and alkaline earth metal salts, and is thereafter washed well withcyvafi,

ter and dried, and heated in an inert atmosphere to about ared heat, after which hydrogen is passed thereover, at a temperature of from 300 C. up to a redheat, and thereafter molten cerium (prepared in theabove manner) is atomized by means of a jet of hydrogen gas under pressure, uponrthe granular. charcoal, which be contained. in a rotating drum, in order to give granular charcoal which is lightly and more or ,"less 8o uniformly coated, and somewhat impregnated, with finely divided metallic cerium, containing the above mentioned raregmeta ls, which material will constitute thelcontact mass preferably used in my process, -but?l other catalysts, within the scope of the appended claims, may he used. The contact mass as above, or otherwise prepared, is

then placed in a tube and heated we temperature of about-300 to 600 Q, preferably-W0 about 350 C. to 450 (1., and a mixture bif hydrogen and nitrogen, preferably in the approximate proportions of 3:1 by volume, is then passed thereover, while under pres- I sure; A pressure of 60 to '80 atmosphrbs (900 tolil'lO pounds per square inch) iy'es, excellent results. 7

The action of the catalytic is-to' convert a part of the nitrogen and hydrogen intom ammonia, which may be removedfrom fille gas mixture leaving thcconta'ct chamberby any suitable method, for example, by'ipas fsing'the gasesin contact with sulfuriclor other acid, to form ammonium salesmen, as sulfate, or in contact with highly acid su-' perphosphate thereby forming ammoniat'ed superphosphate, which is a 'valuablefertihzer. The remaining gases, containinghydrogen and nitrogen, after drying purifying if necessary, are then passed to-' I. sure as is present in the contact n order to avoid excessive use of the expense lnciolent thereto.

gether with more of the mixture of hydrowhich may be removed in the same manner,

The absorption of ammonia should preferably take place while the gases" are maintained under substantially the same presapparatus, power, and Thus is established a closed circuit of gas under pres sure, from the gas holder through the contact chamber, to and through the absorber, and back to the gas holder, while additional gaseis constantly-added in amounts substantially equal to the amounts of nitrogen and hydrogen converted into ammonia.

The gases may pass through a series of alternated contact chambers and absorption chambers, and then if any considerable amount of hydrogen and nitrogen remain uncomhined, they may pass back to the gas holder.

The mixture of hydrogen and nitrogen used should be as free as possible from oxygen, Water, sulfur compounds and carbon dioxid, but small amounts of carbon monoxid and certain other gases do-not appear l absorbing,

ratio exists,

'lncrease and when to be particularly uents. v

In passing the gases repeatedly over the contact mass, any excess of either injurious, except as "'dilically the gases in or entering the contact chamber should be tested to see that this and any material variation therefrom should be compensated for by ap- 'propriate additions of gas. Also if any considerable amount of inert diluents are present in the gases, these will progressively the amount of diluents gets high, the gas'should be allowed to escape to waste, or be otherwise utilized, or

"the diluents removed by appropriate methods, e. (7., if the diluents consist largely of CO, the may be removed by liquefaction, after which the hydrogen and be returned to the process. a

It will,' be noted that the porous charcoal, treated as above described is an excellent hydrogen occluding agent, beingctpable of occluding, taking up, and hold- 1ng many times its volume of hydrogen.

Cerium is also well known to 'unite'with free nitrogen to form cerium nitrid. Hence the preferred catalyst employed comprises a hydrogen occluding agent (the charcoal) having maculated or coated thereupon, a

agent, (cerium) and containing activating agents (yttrium, etc). Aside from this, the cerium itself acts as a catalyst, of great power, in producing the union of hydrogen and nitrogen.

While I have described my process in great detail, I do not limit myself to these the action of a mixture of gas over the ratio of 3:1 will accumulate, and periodnitrogen may The catalyzer comprising cerium or simi- I larly acting metal, will under some conditions be partially or entirely converted by hydrogen and nitrogen, into nitrid or other nitrogen-containing body, which body exercises substantially the same effect as metallic cerium, or in other words the catalytic activity of the cerium or similarly acting metal is not materially lowered by the conversion of all or a portion thereof into nitrid or other nitro-. gen-containing body. Accordingly inthe appended claims, the'expressions'cerium tetravalent metal having the property of catalytically causing the union of hydrogen and nitrogen, catalytic metal having the property of aiding the union of hydrogen and nitrogen, nitrogen-occluding substance metal in a non-oxidized condition, metallic cerium containing activating agents, metal of the cerium group capable of effecting the combination of hydrogen and nitrogen, catalytic metal of the cerium group, catalytic substance containing a metal substance containing a .metal which in'the free state is capable of combining with nitrogen and similar expressions are intended to cover either the metal in the free or metallic state, or the metal in an active condition, as regards its possession of capability of catalytically effecting the combination of hydrogen and nitrogen, although said metal may not be in the free state, but may be in the form of a nitrogen-containing compound, or other compound of said metal.

It is also possible that the catalytic Suk -:3.

stance when containing cerium and another vmetal mayreact'either with the said other metal, or with or with hydrogen, or with ammonia, these substances with the production of more complex bodies than nitrids, and such complex compounds are likewise intended to, be included within the scope of the appended claims. r

What I claimisz- 1. A process oi making ammonia which comprises passinga gas mixture containing hydrogen and nitrogen into contact Witha catalyzer containing a porous base carrying cerium and another substance capable of increasing the catalytic activity thereof.

2. A process of making ammonia which comprises passing a ga's'mixture containingnitrogen,

" hydrogen and nitrogen into contact with a.

catalyzer containing a tetravalent metal having theproperty of catalytically causing the union of hydrogen and other metal capable of increasing the-catalytic activity. i

' 3. A process of making 'ammonian which comprises passing a gas mixture containing hydrogen and nitrogen into contact with 'a 130 or with two or more of" nitrogen, and an- 21. process of making ammonia which campuses bringing a mixture of gases con 1 tai'ning hydrogen and nitrogen into contact Wlth a catalyst comprising a carbonaceous base associated with a nitrogen-occluding agent. a 1

22. A process of synthetically producing ammonia which' 'pomprises bringing a gas its surface with a nitrogen-occlu mixture comprising into contact'with a base or carrier permeable to gases said carrierbeing coated, over at least a (portion of ing agent metals in a nonmaintaining said hydrogen and nitrogen comprising a plurality of oxidized condition, while gas mixture under a pressure'between about 60 and about 100 atmospheres.

23, A process of making ammonia which comprises passing a gas mixture comprising ydrogen and nitrogen in the proportions of about 3 :1 by volume, in contact with a cata lyst comprising metallic cerium containing activating agents, maculated upon porous,

granular, absorptive charcoal free from soluble materials. 24. The process of making. ammonia which comprises bringing a mixture of gases containing hydrogen and nitrogen and essentially and substantially free from moisture and oxygen under a pressure of 60 to 8O atmospheres into contact with a catalyst comprising a granular porous carrier having a nitrogen occluding agent supported thereon. i

25. The process of making ammonia which comprises bringing a mixture of a'ses containing hydrogen and nitrogen un er a ,pressure of about 60 to 80 atmospheres into .contact with a catalyst comprising a carrier having a nitrogen occluding agent supported thereon.-

26. A process of making ammonia,

which comprises passing a gas mixture containmg hydrogen and nitrogen, but substane which comprises passing tially free from both moisture and ogygen, into contact witha catalyst comprising a metal of the cerium group which has the property of effecting the combination of hydrogen and nitrogen. r e

27. A process of making ammonia a gas containing hydrogen and nitrogen, at pressure of about "0 to',, 80" atmospheres, into contact With a catalyst comprising a'metal of the taining said gas mixture uni between about 60 cerium group which has the property of cf footing the fcombination. of hydrogen and nitrogen 28. A": .prkices's of, making ammonia which comprises'p'assing a gas mixture comprising h drogen and nitrogen While mainer a pressure of and about fiflatmospheres,

' into contact with. -a catalytic body comppis- --ing a catalytic sudstance capable of causing 1 the combination of hydrogen and nitrogen.

29. A process" or making ammonia which comprises passing a gas mixture comprising hydrogen and nitrogen while at a pressure not materially :below 60 atmospheres and not materially above 90 atmospheres, into contact with a catalytic body comprising a catalytic substance containing a metal capable of combining with nitrogen and adapted to catalytically effect the combination of hydrogen and nitrogen, said sub stance being deposited upon a suitable porous carrier.

30. A process of making ammonia which comprises passing a gas mixture which containshydrogen and nitrogen while at a pressure materiallyless than 100 atmospheres, into contact with a catalytic body comprising a catalytic substance adapted to cause the combination of hydrogen and nitrogen, deposited upon a suitable carrier. 31. A process of making ammonia by synthesis which comprises subjecting amixture comprising hydrogen and'nitrogen in the substantial absence of catalyzer poisons at a pressure between about 60 atmospheres and about atmospheres to the action of a catalytic body, at a temperature of between about 350 0., and about 600 0., said catalytic body comprising a base which is porous to gases, property of catalytically effecting the combination of hydrogen and nitrogen, said substance containing a metal which in the free state is capable of combining with nitrogen. 32. A process of making ammonia by synthesis which comprises subjecting a mixture comprising. hydrogen and nitrogen in the substantial absence of catalyzer poisons at a pressure between about 60 atmospheres 'and about 90 atmospheres to the action of a catalytic body, at a temperature ofbetween about 350 C. and about 600 (1., said catalytic body comprising a base which is porous to gases, carrying a substance having the bination of hydrogen and nitrogen, said carr in a substance havin thesubstance containing a metal which in the free state is capable of-combining with nitrogen, removing the formed ammonia from the 1; mixture, and again bringing the re sulting gas mixture into contact with a catalytic body of the nature stated.

33. A process I which comprisespassing a gas mixture comprising hydrogen and nitrogen into a contact chamber containing a catalytic body comprising a porous base having gas-absorptive properties and having deposited thereupon a material capable of catalyticallv efl'ecting the combination of hydrogen and nitrogen, said material including. a mbtal in a non-oxidized condition, which metal is capable of combining with free nitrogen, and maintaining a pressure in the contact chamber between about 60 atmosof making ammonia pheres and about 80 atmospheres, and mainstaining said catalytic body at a temperature containinglmdrogen and nitrogen, in eontact with a catalyst comprising a base which is permeable to gases having coated thereupon a non-oxidized serium-c0ntaining maserial capable ofeatalytically efieeting the union of hydrogen and nitrogen coated, hile said gas mixture is maintained atfa pressure bebweenabont 60 and 90 atmospheres.

35. 'Alproeess of producing ammonia from its elements which coinprises'subjeeting a nitrogen-occluding agent, in the non-0x1- dized condition, to the action of hydrogen.

and nitrogen at. a pressure ofabout 60 to 90 atmospheres, while carried by and supported upon a non-pnlveru1ent base or carrier which is permeahle to said gas mixture, and

While said agent 1s maintained at a temperature favoring its property of effecting the catalysis of ammonia from its elements, and while in the absence of catalyzer poisons capable of deleteriously afieoting said a ent.

In testimony whereof I have aflixe my signature hereto. v

O'ARLETON'ELLIS. 

